<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
.button {
  background-color: #f4511e;
  border: none;
  color: white;
  padding: 16px 32px;
  text-align: center;
  font-size: 16px;
  margin: 4px 2px;
  opacity: 0.6;
  transition: 0.3s;
  display: inline-block;
  text-decoration: none;
  cursor: pointer;
}

.button:hover {opacity: 1}
</style>
</head>
<body>

<h1>淡入按钮 - 淡入效果</h1>

<button class="button">请悬停在我上方</button>

</body>
</html>
